Don't encourage the use of display-buffer-alist from Elisp code.

Don't encourage the use of display-buffer-alist from Elisp code.
* lisp/window.el (same-window-buffer-names, same-window-regexps)
(special-display-frame-alist, special-display-popup-frame)
(special-display-function, special-display-buffer-names)
(special-display-regexps, pop-up-frame-alist)
(pop-up-frame-function, pop-up-frames, display-buffer-reuse-frames)
(pop-up-windows, split-window-preferred-function)
(split-height-threshold, split-width-threshold, even-window-heights)
(display-buffer-mark-dedicated): Fix obsolescence info.